Filter media loading arrangement for roll-type air filter



Jan. 10, 1967 A. E. REVELL 3,296,780

FILTER MEDIA LOADING ARRANGEMENT FOR ROLL-TYPE AIR FILTER Filed. July 30, 1963 INVENTOR.

ALAN E. REVELL ATTORNEY United States Patent Ollice 3,296,780 Patented .Ian. 10, 1967 3,296,780 FILTER MEDIA LOADING ARRANGEMENT FOR ROLL-TYPE AIR FILTER Alan E. Revell, Louisville, Ky., assignor to American Air Filter Company, Inc., Louisville, Ky., a corporation of Delaware Filed July 30, 1963, Ser. No. 298,677 4 Claims. (Cl. 55354) This invention relates generally to roll-type air filters, and has as its principal object the provision of an improved supply zone construction facilitating supply roll loading. The object is accomplished with an inexpensive, simple arrangement of parts disposed in a relationship which yields the desired result.

The ease of loading supply rolls of filter material in roll-type air filters may seem to be a factor of minor concern in the air filtering art as a whole. However, the rolls are frequently of sufficient size and weight as to be characterized as unwieldly from a handling standpoint, and the difficulties experienced in loading are compounded by the fact that such air filters frequently have a supply section portion into which the rolls must be installed located at a height that the loader must not only elevate the rolls above his head but also use a step ladder. Further, these roll-type filters are often installed in banks having a substantial number of sections, each of which is separately loaded. Thus it will be readily appreciated that it is desirable to provide an arrangement in which the loading difliculties are minimized to the degree possible consistent with a reasonable cost structure, and it is to this end that the present invention is directed.

In accordance with the present invention, a construction is provided which facilitates the loading of the supply roll by both centering it in a sideways direction and by providing support in a vertical direction during the loading operation. The support arrangement is such that support for the roll during loading is transferred smoothly from the rims to projecting spindles of the roll by simply pushing the roll into place. The sideways centering is likewise effected by simply pushing the roll into an initial position of insertion.

As to the general structure according to the invention, the supply section housing into which the roll is loaded includes fixed end walls carrying bearing means which receive the projecting end spindles of the supply roll, a bottom wall, and a forward open face through which the supply roll is inserted. Ramp means which serve to guide and support the roll during loading are secured to the inner faces of the end walls and extend between the bearing means and the forward open face of the housing. The upper surfaces of these ramp means support the roll end spindles during passage of the roll to its operative position. To insure a smooth transfer of support of the roll from an initial position of loading wherein the rims rest upon the housing bottom wall to a successive intermediate loading position wherein the spindles rest upon the upper surfaces of the ramp means, the forward ends of the ramp means are disposed above the lower edge of the forwardly open face of the housing a distance slightly less than the radius of the rims of the supply roll. Thus in the initial position of loading the spindles overlie the forward ends of the ramp means, and by simply pushing the roll towards its final position support for the roll is transferred from the rims to the spindles. The initial lateral centering of the roll is promoted by providing tapering inner edges on the opposite ramp means, the tapering edges lying in converging relation to each other in a frontto-rear direction. When a roll being loaded is off center to a degree that one or the other of the splindles would catch against a vertical edge of the forward open face,

one of the tapered edges is contacted by the respective rim of the roll, and the roll is thereby urged toward a sideways centered position.

The invention will be described in connection with the accompanying drawing illustrating an embodiment thereof by the way of example, and wherein:

FIGURE 1 is a perspective view of the upper or supply zone end of a roll-type air filter embodying the ll'l-i vention, with the door forming the forward wall of the supply zone in an open position exposing the interior of the supply roll housing;

FIGURE 2 is an enlarged fragmentary isometric view of one interior end of the supply roll housing;

FIGURE 3 is a vertical sectional view of the supply roll housing with a roll of the filter material installed, this view corresponding to one taken along the line 3-3 of FIG. 4 and with a broken-line outline illustrating the supply in an initial position during loading;

FIGURE 4 is a horizontal sectional view corresponding to one taken along the line 4-4 of FIGURE 3.

The invention is illustrated herein as incorporated in a roll-type air filter which is combined with an electrostatic precipitator to form a compact device having a relatively small dimension in the direction of air flow. Those parts of the combined filter device which underlie the supply zone are of no particular importance with respect to this invention and therefore are not shown. They will be described only to that extent which facilitates an understanding of the environment in which the invention finds one application.

The supply roll housing portion of the air filter is shown in FIGURE 1 with the loading door through which the supply roll is inserted in an open or dropped position. After a new supply roll (not shown in FIGS. 1 or 2) has been placed in its operative position in the housing, the filter material is threaded off the top side of the roll and passed to the rear face 2 of the filter over the top of a fluted roller 4. The material is then directed downwardly along the rear face of the filter between the spaced apart upstream and downstream vertical rods 6 and 8 which support the filter material against either upstream or downstream displacement in the air fiow zone. At the bottom of the rear face the leading end of the material is directed forwardly for attachment to a rewind spool (not shown) at the bottom of the filter and generally below the supply zone. The vertical space etween the supply zone at the top, and the rewind zone at the bottom, is occupied by the electrostatic precipitator section. During operation of the filter, increments of the filter material are pulled from the rotatable supply roll and advanced into the air stream as needed, as is conventional practice with roll-type filters.

The supply roll housing includes a top wall 10, opposite end walls 12, a bottom wall including an elevated forward section 14 and a depressed rear section 16, and the door 18 forming the forward wall when closed. The rear section 16 of the bottom wall terminates short of the rear face of the filter to permit the passage of the filter material downwardly along that rear face between the vertical rods 6 and 8. When closed, the door 18 substantially seals the supply zone against air flow therethrough. As shown, the door is hinged along its bottom edge to the forward section 14 of the bottom wall so that it can be dropped to permit removal of the empty spool after the filter material has been exhausted.

The supply roll of filter material 20 is shown in its installed position in FIGURES 3 and 4. As is conventional, supply roll is formed by winding filter material on a mandrel or core 22 which carries fixed end discs 24 at opposite ends of the core to confine the filter material in its wound form to the proper width. The most commonly used filter material for roll-type filters is of an expansible-compressible character which requires confinement by the end discs 24 to prevent lateral displacement beyond the proper end limits when the material is compressed on the core. Stub axles or spindles 26 are removably inserted into the opposite ends of the core 22 and project outwardly from the end disc. The spindles are journalled in bearing means secured to the inner faces of the opposite end walls when the roll is in its operative position.

The bearing means on each end wall is substantially the same as its counterpart on the opposite end wall except for being in mirror relation thereto. Therefore a single numeral is used to designate any part which is the same for both bearing means. As best shown in FIG. 2, the bearing means may conveniently be made in the form of a box-shaped member or bracket 28 provided with an upwardly-open vertical slot 30 in that wall of the bracket which is spaced inwardly from and parallel to end wall 12. The material defining the rear edge of the slot projects above the forward edge of the slot to provide a stop which assures entry of the supply roll spindles 26 into the slot when the supply roll is pushed rearwardly into position.

The members which guide and support the supply roll during its passage from an initial position of insertion to its operative position are generally designated 32, and are secured to the inner faces of the end walls 12 in mirror relation to each other as in the case of the bearing means. Each member 32 extends from the forward edge of its associated bracket 28 to the forward face of the supply roll housing. The members 32 are generally L-shaped in cross-section, with one leg of uniform width 34 lying against the inner face of the end wall 12, and the other leg 36 projecting inwardly from the wall and tapering in a rear-to-front direction. Thus the inner edges 28 opposite of the tapering legs 36 lie in converging relation with each other in a front-to-rear direction.

Each member 32 is secured with the upper surface of its rear end, i.e., the end adjacent the bearing means, at the same height as the forward edge of the slot 30. The forward end of member 32, i.e., the end adjacent the forward face of the supply housing, has its upper surface spaced above the forward section 14 of the bottom wall a distance slightly less than the radius of the end rims 24 of the supply roll. The spacing of the forward end is perhaps best shown in FIGURE 3 where the supply roll is shown in an initial position of insertion with the bottom edge of the rim 24 resting upon the upper surface of the forward section 14 of the bottom wall, and with the projecting spindles 26 in a position overlying the upper surface of the forward end of the member 32. By virtue of this spacing arrangement, loading of a roll of filter material is facilitated in that the roll is simply elevated to a height that the end rims 24 can be rolled onto the forward section 14 of the bottom wall and this will automatically dispose the projecting spindles 26 above the forward end of the members 32. Then as the roll is pushed rearwardly into the housing, support of the roll by the rims upon the bottom wall is transferred smoothly to a condition of support of the spindles 26 upon the surfaces 36. After the roll has been pushed rearwardly as far as possible, the spindles overlie and drop into the slots 30 of the bearing means. The leading end of the filter material 20 is then threaded off the top of the roll and passed rearwardly over the fiuted reel 4 and is pulled down along the rear face 2 as previously described.

The rims 24 also cooperate with the tapered edges 38 of the members 32 to facilitate lateral centering of the supply roll with respect to the housing during the roll loading operation. As perhaps best shown in FIGURE 4, the spacing between the opposite end rims 24 upon the core 22 is slightly less than a distance between the inner faces of the bearing brackets 28. During loading, if the 0.11 i laterally Ofi 9991.6! to an extent that either one of the spindles 26 would catch upon either of the respective vertical flanges defining the vertical edges of the loading opening, contact between the one end rim 24 and the respective tapered edge 38 as the roll is pushed rearwardly will urge the roll sideways toward a sufiiciently centered position that the spindles will miss the vertical flanges.

From the foregoing, it will be appreciated that when a supply roll is inserted it need only be elevated to a sufficient height that the rims 24 rest on the forward section 14 of the bottom wall and that sideways centering is effected, to the degree that it is necessary, by contact between a rim and a tapered edge 38. Then the roll is simply pushed rearwardly until the spindles 26 drop into place in the slots 30. Thus the difficulties experienced because of the unwieldly nature of the larger, heavier rolls, and the frequently substantial height above the floor of the supply section housing location, are largely minimized by virtue of the described construction.

Having described my invention, I claim:

1. A roll-type air filter of the type including a filter medium supply section, a filter medium rewind section, an open face air passage intermediate the supply section and said rewind section, filter medium extending through said air passage from said supply section to said rewind section so all air to be filtered is passed through said medium in said air passage, where said filter medium in said supply section is wound upon a mandrel having end rims and spindles projecting outwardly from said end rims, including an improved filter medium supply section comprising:

(a) a housing including fixed end walls, a forward open face through which said roll is inserted, and a bottom wall;

(b) bearing means projecting inwardly from the inner faces of said end walls to receive said spindles in nesting relation and support said spindles with said rims therebetween when said roll is in operative position;

(c) ramp means extending forwardly and inclined downwardly from each of said bearing means toward said forward open face,

(i) each of said ramp means providing an upper surface supporting said spindles during movement to said bearing means position with the forward ends of said upper surfaces being spaced a distance above said bottom wall slightly less than the radius of said end rims so the center of said projecting spindles is above said forward end of said upper surface when said roll of filter medium rests on said bottom wall,

(ii) said ramp means having opposing edges spaced in converging relation in a front-to-rear direction to provide for lateral centering of said roll during insertion by contact of either of said rims with its respective edge of said ramp means.

2. In a roll-type air filter of the type including a filter medium supply section, filter medium rewind section, an open face air passage intermediate said supply section, and said rewind section, filter medium extending through said air passage from said supply section to said rewind section so all air to be filtered is passed through said medium in said air passage and where said filter medium in said supply section is wound on a mandrel having end rims and spindles projecting outwardly from said end rims, an improved supply section comprising:

(a) a housing including end walls between which said roll is supported after insertion through the forwardly open face of said housing, and a bottom wall;

(b) means forming a pair of upwardly-open slots spaced inwardly from the inner faces of said end walls for supporting said spindles with said mandrel end rims therebetween when said roll is in 0perative position;

(c) ramp means extending forwardly and inclined downwardly from said slots to provide support and lateral centering of said roll during loading,

(i) each of said ramp means including an upper surface having its forward end spaced above said bottom wall a distance slightly less than the radius of said rims so said projecting spindles are above said forward end when said roll of filter medium rests on said bottom wall,

(ii) said ramp means further including opposing edges spaced in converging relation in a front-torear direction to provide for sideways centering of said roll during insertion by contact of one of said mandrel end rims with the respective edge of said ramp means.

3. In a roll-type air filter of the type including a filter medium supply section, a filter medium rewind section, an open face air passage intermediate supply section and said rewind section, filter medium extending through said air passage from said supply section to said rewind section so all air to be filtered is passed through said medium in said air passage and where said filter medium is wound on a mandrel having end rims and spindles projecting outwardly from said end rims, and improved supply section comprising:

(a) a housing for said roll including stationary end walls and an open forward face, a bottom portion;

(b)bearing means mounted on the opposing inner faces of said end walls for supporting said spindles;

(c) inclined ramp means for guiding and supporting said roll during loading thereof through said open forward face of said housing,

(i) said ramp means including upwardly inclined upper surfaces extending along the inner face of each said end wall from a forward edge adjacent said housing open face to said bearing means to support said spindles during movement of said roll from said housing open face to an operative position where the forward edge of said ramp is adjacent said forward face and is spaced above said bottom wall a distance slightly less than the radius of said rims so said projecting spindles are slightly above said forward edge of said ramp means when said roll of filter medium rests on said bottom wall, and further including opposing inner edges lying in converging relation in a front-to-rear direction to effect lateral centering of said roll by contact of either of said rims with one of said respective inner edges.

4. In a roll-type air filter of the type including a filter medium supply section, a filter medium rewind section, an open face air passage intermediate the supply section and said rewind section, filter medium extending through said air passage from said supply section to said rewind section, so all air to be filtered is passed through said filter medium and said air passage and where said filter medium is wound on a mandrel having end rims and spindles projecting outwardly from said end rims, an improved supply section comprising:

(a) a housing including fixed opposite end walls, a forward wall hinged along its bottom edge, and a bottom wall to which said forward wall is hinged;

(b) bearing means mounted on the inner faces of said end walls to support said roll in its operative position, said bearing means including upwardly open slots adapted to receive said spindles;

(c) ramp means joined to the inner surface of said opposite end walls extending outwardly toward each other and inclined upwardly from said forward wall to receive and support a spindle during passage of said roll through the forward open face of said housing to an operative position in which said roll is supported by said bearing means,

(i) each ramp being disposed with the forward end of its upper spindle supporting surface spaced above said bottom wall a distance slightly less than the radius of said rims so said spindles are disposed above said forward end of said ramp means to facilitate the smooth transfer of support of said roll from a position wherein said rims rest on said bottom wall to a position wherein said spindles rest upon said upper surfaces, and

(ii) each ramp further having an inner edge which lies in converging relation with the inner edge of the opposite ramp to effect lateral centering of said roll with respect to said housing by contact of either of said rims with the respective inner edge.

References Cited by the Examiner UNITED STATES PATENTS 1,537,673 5/ 1925 I-Iillyard. 1,759,113 5/1930 Hegarty 210-241 X 1,973,354 9/1934 Hebberg 242552 X 2,055,873 9/1936 Manning 210387 2,106,187 1/1938 Naugler. 2,369,970 2/ 1945 McClearen 242552 2,808,899 10/1957 Hofstetter 55354 2,875,680 3/1959 Forshee 55354 X 2,881,859 4/1959 Nutting 55354 X 2,930,663 3/1960 Weiss 31238 2,953,821 9/1960 Ingham 24258.6 X 3,007,651 11/1961 Palmore 55354 X 3,176,928 4/1965 Saunders 24258.6 3,184,176 5/1965 Tucker et al 24255.3

FOREIGN PATENTS 541,501 10/1955 Belgium.

746,162 3/ 1956 Great Britain.

902,203 8/ 1962 Great Britain.

HARRY B. THORNTON, Primary Examiner.

D. E. TALBERT, JR., Assistant Examiner. 

1. A ROLL-TYPE AIR FILTER OF THE TYPE INCLUDING A FILTER MEDIUM SUPPLY SECTION, A FILTER MEDIUM REWIND SECTION, AN OPEN FACE AIR PASSAGE INTERMEDIATE THE SUPPLY SECTION AND SAID REWIND SECTION, FILTER MEDIUM EXTENDING THROUGH SAID AIR PASSAGE FROM SAID SUPPLY SECTION TO SAID REWIND SECTION SO ALL AIR TO BE FILTERED IS PASSED THROUGH SAID MEDIUM IN SAID AIR PASSAGE, WHERE SAID FILTER MEDIUM IN SAID SUPPLY SECTION IS WOUND UPON A MANDREL HAVING END RIMS AND SPINDLES PROJECTING OUTWARDLY FROM SAID END RIMS, INCLUDING AN IMPROVED FILTER MEDIUM SUPPLY SECTION COMPRISING: (A) A HOUSING INCLUDING FIXED END WALLS, A FORWARD OPEN FACE THROUGH WHICH SAID ROLL IS INSERTED, AND A BOTTOM WALL; (B) BEARING MEANS PROJECTING INWARDLY FROM THE INNER FACES OF SAID END WALLS TO RECEIVE SAID SPINDLES IN NESTING RELATION AND SUPPORT SAID SPINDLES WITH SAID RIMS THEREBETWEEN WHEN SAID ROLL IS IN OPERATIVE POSITION; (C) RAMP MEANS EXTENDING FORWARDLY AND INCLINED DOWNWARDLY FROM EACH OF SAID BEARING MEANS TOWARD SAID FORWARD OPEN FACE, (I) EACH OF SAID RAMP MEANS PROVIDING AN UPPER SURFACE SUPPORTING SAID SPINDLES DURING MOVEMENT TO SAID BEARING MEANS POSITION WITH THE FORWARD ENDS OF SAID UPPER SURFACES BEING SPACED A DISTANCE ABOVE SAID BOTTOM WALL SLIGHTLY LESS THAN THE RADIUS OF SAID END RIMS SO THE CENTER OF SAID PROJECTING SPINDLES IS ABOVE SAID FORWARD END OF SAID UPPER SURFACE WHEN SAID ROLL OF FILTER MEDIUM RESTS ON SAID BOTTOM WALL, (II) SAID RAMP MEANS HAVING OPPOSING EDGES SPACED IN CONVERGING RELATION IN A FRONT-TO-REAR DIRECTION TO PROVIDE FOR LATERAL CENTEING OF SAID ROLL DURING INSERTION BY CONTACT OF EITHER OF SAID RIMS WITH ITS RESPECTIVE EDGE OF SAID RAMP MEANS. 